Tubular goods for installation in wells experience considerable handling and storage between steel mill and well and a cylindrical thread protector normally stays on every male thread until it reaches the well site. These are screw on protectors and have a full complement of threads. It takes a number of turns to remove the original protector and that expenditure of time cannot be tolerated during installation of tubular strings in wells. The original protector is removed at the well site and a quick releasing one is installed. It rides from rack to rig and is removed when the joint is to be threadedly attached to the downwardly continuing string. During the interval that the protector is on threads, a last bore drift test is usually done and it is desirable that the protector does not interfere with the drift passage.
A considerable amount of development work has been done in efforts to improve the bands and related tensioning gear to keep the casing protectors from being knocked off the thread during the rack to well trip.
The body of protectors in rig site use are currently made of elastomer, usually polyurethane, but sometimes black rubber. The elastomer is formulated and cured to serve the skid and bash protection function and does not always favor thread gripping. The elastomer would grip threads if enough hoop force were applied by the securing bands. The securing bands that are closed by hand have limited energy available and do not drive the elastomer into the thread grooves sufficiently to prevent occasional slipping of the protector.
It is therefore an object of this invention to provide an elastomeric thread protector with higher unit loading to more effectively urge the elastomer into the thread grooves yet allow drift testing of the pipe bore.
It is another object of this invention to provide replaceable elements subject to the higher unit loading to reduce the frequency of total body losses due to thread load induced damage.
It is yet another object of this invention to provide a tensioning hoop band for closing thread protectors on pipe threads that is readily replaceable when damaged to preserve the elastomeric body.
These and other objects, advantages, and features of this invention will be apparent to those skilled in the art from a consideration of this specification, including the attached claims and appended drawings.